mony, Majestic, Olympia, and Fascination. The majority of the melons trialed weighed between 15 and 18 pounds. Fruit quality was generally high in this trial with the av-erage percentage of cull fruit in each variety ranging from 0.9 to 1.8% of total har-vested weight and melons usually had sugars be-tween 11-12%. Aver-age fruit length and width were recorded as well. This data is pre-sented in Ta-ble 1 as a length to width ratio in order to rep-

SEEDLESS WATERMELON VARIETY UPDATES

Tim Coolong, Extension Vegetable Specialist

Kentucky Vegetable Growers Newsletter M A R C H 2 0 1 2 S P R I N G I S S U E

Vaden Fenton, Fruit & Vegetable Extension Associate, Editor Tim Coolong, Extension Vegetable Specialist, Editor

Back in May of 2010, we confirmed a A number of larger growers in Western Ken-tucky have begun growing seedless water-melons. Traditionally seedless melons have been round or oval, with only a few, namely ‘Revolution’ and ‘Matrix’ having an oblong shape, similar to traditional seeded melons. However, despite being less common the oblong type melons seem to be better suited to packing in large bins. It seems that the round melons are often difficult to pack in a way that ensures a consistent number of fruit in a bin. Several new varieties of oblong and round seedless watermelons have been released over the past few years so we decided to trial 30 of these melons in Lexington in 2011. The melons were grown as recommended for seedless melons in Kentucky using ‘Ace’ as a pollenizer spaced between every 3rd and 4th plant. White on black plastic was used in place of black plastic mulch since the watermelons were transplanted the first week of June when temperatures were high. The results are shown in the table below. The growing season of 2011 was warm with regular rainfall and yields were good. Crunchy Red had the highest yield in pounds/acre, though was closely followed by Matrix, Crisp N Sweet, Majestic and Harmony (Table 1). Ten varieties had yields exceeding 90,000 pounds/acre. The highest yielding variety in number of fruit/acre was Fenway, which averaged 6610 fruit/acre. Several other varieties including Crunchy Red, Majestic, and Nomad all averaged more than 6000 fruit per acre. The largest fruit were recorded for the vari-ety Matrix, which averaged 20.2 pounds/fruit. Other varieties with average fruit weights of 18 pounds or more included Revolution, HSR 4618, HSR 4620, Har-

resent the shape of a melon. The greater the length to width ratio the more elongated the melon. Varieties displaying elon-gated characteris-tics varieties in-cluded: HSR 4620, HSR 4618, Revo-lution, and Matrix. Varieties that were nearly round in appearance in-cluded: Fenway,

Nomad, Gypsy, 4502 Seedless, and SWT 7138.

Although this was only one year of re-sults, many growers around Kentucky have trialed some of our top yielders successfully.

Crunchy Red was our highest yielder

Melons were grown on white plastic. A preplant applica-tion of Command and Curbit, with a post transplant appli-

cation of Sandea provided good control of weeds.

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Table 1. Total yield, average fruit weight, percent culls, soluble sugars and the length to width ratio are presented for 30 varieties of seedless watermelon grown in Lexington, KY in the summer of 2011. Varieties are ordered based on total yield in pounds/acre. Variety Total Yieldz

Average Fruit Weight Cully

Soluble Sugars

Length/Widthx

(Pounds/Acre) (Fruit/Acre) (Pounds/Fruit) (%) (%) (Ratio)

Crunchy Red 106,280 av 6050 ab 17.8 bcdef 1.0 11.8 1.3

Matrix 104,750 ab 5206 abcd 20.2 a 0.9 11.5 1.6

Crisp N Sweet 102,270 abc 5440 abc 18.9 abcd 1.1 11.7 1.4

Majestic 100,900 abcd 6090 ab 16.7 defgh 1.0 12.1 1.2

Harmony 100,580 abcde 5470 abc 18.3 abcde 1.2 11.6 1.2

Nomad 99,930 abcde 6090 ab 16.7 defgh 1.1 11.7 1.1

HSR 4618 99,290 abcdef 5190 abcd 19.2 ab 1.0 11.5 1.5

Olympia 96,240 abcdefg 5100 bcd 18.9 abcd 1.1 11.9 1.2

HSR 4620 96,150 abcdefg 5060 bcd 19.0 abc 1.1 11.0 2.1

Fenway 92,000 bcdefgh 6610 a 13.8 ij 1.2 12.0 1.0

7197 HQ 84,700 bcdefghi 4860 bcd 17.4 bcdefgh 1.3 11.3 1.4

Vagabond 83,680 cdefghij 5440 abc 15.4 hi 1.3 11.5 1.2

Liberty 83,320 cdefghij 5250 abcd 15.9 fghi 1.3 11.7 1.2

Fascination 83,250 cdefghij 4490 cd 18.5 abcde 1.3 11.0 1.2

Cooperstown 81,530 defghij 4930 bcd 16.6 defgh 1.3 12.0 1.2

Revolution 80,980 defghij 4470 cd 18.3 abcde 1.3 11.6 1.6

Melody 80,530 efghij 5060 bcd 16.0 fghi 1.3 11.7 1.3

HSR 4624 79,320 fghij 5100 bcd 15.6 fghi 1.4 11.3 1.4

Declaration 78,050 ghij 4540 cd 17.3 bcdefgh 1.4 10.9 1.2

Summer King 77,180 ghij 4930 bcd 15.9 fghi 1.4 11.5 1.2

Troubadour 76,320 ghij 5530 abc 13.9 ij 1.5 11.1 1.1

7167 74,390 hij 4540 cd 16.5 efgh 1.5 11.7 1.2

Gypsy 72,800 hij 4490 cd 16.3 efgh 1.5 11.9 1.0

Sweet Delight 71,023 ij 4150 cd 17.2 bcdefgh 1.5 11.3 1.2

Bold Ruler 69,600 ij 4540 cd 15.4 ghi 1.6 11.9 1.1

Sweet Treasure 68,440 ij 3850 d 17.8 bcdefg 1.6 10.5 1.2

SWT 7138 67,570 ij 5250 abcd 12.9 j 1.6 10.7 1.0

4502 Seedless 67,220 ij 3850 d 17.7 bcdefg 1.7 11.3 1.1

Tri X 313 66,990 ij 3890 d 17.3 bcdefgh 1.6 10.9 1.2

Nun 1000 64,380 j 3850 d 16.8 cdefgh 1.8 11.2 1.2

z Yields based on a plant population of 2074 plants per acre y Percentage of cull calculated by dividing weight of cull fruit by the total harvested weight of fruit (marketable + cull) x The ratio of length to width will increase as melons become more oblong and approach 1.0 for a spherical melon w Seed sources listed in Appendix A. Many varieties are available through several seed distributors. v Means in the same column followed by different letters were significantly different at P > 0.05 as determined by Duncan’s multi-ple range test.

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NEW FUNGICIDES FOR VEGETABLE PRODUCTION

IN KENTUCKY Kenny Seebold

Extension Plant Pathologist The world of vegetable fungicides has-n’t changed much for a good number years; however, a flush of new products started showing up in the marketplace in 2011 and early 2012. In some cases, these products are new versions of existing fun-gicides. Others are combinations of old and new active ingredients, and some of the new fungicides are novel materials. The following is a brief update on recently-introduced disease control chemicals that vegetable producers may encounter at their local farm chemical dealer or read about in the 2012-2013 Vegetable Production Guide for Commercial Growers (University of Kentucky Publication No. ID-36). Consult product labels for specific information such as application rate, dis-eases controlled, and safety guidelines. Catamaran (FRAC Group M): This product is formulated as a liquid and con-tains chlorothalonil (the active ingredient found in Bravo WeatherStik and generic equivalents) and potassium phosphite. Catamaran is for foliar use, and suppresses a wide range of fungal diseases on beans (snap and dry), carrot, celery, cole crops (broccoli, Brussels sprouts, cabbage, cauli-flower, and Chinese cabbage), corn (sweet), cucurbits (cantaloupe, musk-melon, squash, pumpkin, and zucchini), eggplant, onion, pepper, potato, and to-mato. Greenhouse use is permitted on la-beled vegetables. Fontelis (FRAC Group 7): DuPont introduced Fontelis in early 2012 for use on bean (snap), carrot, cole crops and leafy greens (mustard), cucurbits, garlic, lettuce, onion, pea, pepper, and tomato to suppress a number of fungal diseases. Greenhouse use on cucurbits, pepper, and tomato is permitted. Inspire Super (FRAC Groups 3 and 9): A combination of difenoconazole (found in Inspire) and cyprodinil (found in Vanguard), Inspire Super is labeled as a foliar treatment for control of fungal dis-eases on cole crops and leafy greens (kale, mustard, and turnip), garlic, onion, cucur-bits, and tomato. This product is formu-lated as a liquid.

name of Seminis Performance Series. This is available in three hybrids for 2012.

The potential for damage by insects to sweet corn is dependent on planting date. Early planted corn often escapes insect dam-age in that when it silks and the ears mature, insect pest levels are usually quite low. However, with later planting dates, particu-larly those extending into June or later, corn earworm and fall armyworm levels can be very high during the critical silking period. Corn earworm levels have been so high that it may not be possible to have worm-free ears by relying on insecticide sprays alone. We have had and instance in western Ken-tucky with late planted corn where sweet corn was sprayed with an insecticide every day during silking in late August and the grower still sustained 80% wormy ears due to corn earworm.

Corn earworm can over winter in Ken-tucky in most years, which means that even with early plantings we do have a slight to moderate risk of ear attack. However, as the season progresses, we begin to experience populations emerging from field corn as well as high populations moving into Ken-tucky from southern states on frontal sys-tems. This is when very large populations

Koverall (FRAC Group M): Formu-lated as a dry flowable (DF), Koverall contains the active ingredient mancozeb. This fungicide is equivalent to Dithane DF, Manzate Pro-Stick, and Penncozeb DF, and is labeled for foliar applications on the same crops to control fungal dis-eases. Greenhouse use is permitted on labeled vegetables. Luna Experience (FRAC Groups 3 and 7): Released in early 2012, this product contains tebuconazole (found in Folicur and generic equivalents) and flu-opyram, a new active ingredient. Apply as a foliar spray to control fungal diseases on watermelon. Luna Experience is for-mulated as a liquid. Luna Sensation (FRAC Groups 7 and 11): Luna Sensation is a liquid for-mulation of fluopyram and trifloxystrobin (found in Flint). The product is labeled on watermelon to control fungal diseases. Quadris Top (FRAC Groups 3 and 11): This liquid fungicide contains difenoconazole and azoxystrobin (found in Quadris), and can be used as a foliar spray on carrot, cucurbits, cole crops and leafy greens, eggplant, garlic, onion, pep-per, potato, sweetpotato, and tomato. Quadris Top can be used in the green-house on vegetables grown for produce (not for transplant production).

AN EXPANDED LINEUP OF BT SWEET CORN HYBRIDS FOR 2012

Ric Bessin Extension Entomologist

Insect control is key to producing sweet corn in Kentucky for the late sum-mer and fall markets. We have three in-sects that routinely need to be managed with sweet corn, the corn earworm, fall armyworm, and European corn borer. But year in and year out, the corn earworm is by far the most common insect problem with sweet corn. Bt sweet corn, first ap-proved for use in 1998 as the Attribute series, and been an extremely helpful tool to manage lepidopterous pests of sweet corn late in the year, when pest popula-tions are their most damaging. This fall, Seminis has begun marketing a new type of Bt sweet corn that uses different traits to manage insect pests under the brand

A young corn earworm larva feeding in the tip of an ear.

A fall armyworm larva.

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of egg laying moths may be present. The female moth is most attracted to corn when it silks and remains attracted as long at the silks are fresh. Growers have historically used pyrethroid insecticides during the silk-ing period for corn earworm, but reduced pyrethroid performance at high temperatures combined with reduced sensitivity of corn earworm to pyrethroids have made control in late summer more difficult. Bt sweet corn has improved management of this key pest late in the season.

One of the best methods we have to gauge risk with corn earworm is through the use of pheromone trapping for the male moths. The weekly number of moths cap-tured is used to determine the need and fre-quency of insecticide sprays. While this helps with insecticide sprays, Bt sweet corn decisions need to be made before planting, so our best tool for gauging the need for Bt sweet corn is planting date, and that will vary somewhat with location in the state. Those further to the west and south may see larger populations earlier than those in northern or eastern Kentucky.

Kentucky. The Performance series Bt sweet corn also has the Roundup Ready trait giving growers more flexi-bility with weed control. But with the higher level of insect control and addi-tional weed control comes a higher price for the seed. With both types of sweet corn there are minimum seed lot sizes that need to be purchased of ei-ther 25K or 100K depending on the hybrid. Resistance management is a con-cern when using Bt sweet corn as it is with Bt field corn. Field corn growers using Bt corn have been required to plant a refuge, corn that has no Bt traits in a portion of their field. With Bt sweet corn, growers are required by the EPA to destroy fields within 30 days of harvest. Generally this is done by disking the field shortly after har-vest.

A corn earworm moth.

A fall armyworm moth.

Bt corn has been a valuable tool for growers with later plantings. Low risk with early plantings often does not justify the added expense of the Bt seed. As seed is more expensive, growers position it on their farms to receive the most value of the insect control traits. But Bt sweet corn is not necessarily a silver bullet for insect control and it needs to be used with a scouting program. A seed company that markets the Attribute series Bt sweet corn states that this Bt sweet corn on average results in a 50% reduction in insecticide sprays. The same company markets the Performance series Bt sweet corn and states that it can reduce insecticide use by 85%. The Performance series in addition to controlling ear-feeding worms with two traits instead of one, also has a trait to con-trol western and northern corn rootworm larvae that are pests of continuous corn in

Hybrid Name

Bt Type Days to Matur-ity

Sweet corn type

Kernel Color

BSS 0977 Attribute 78 Sh2 Bicolor

BSS 0982 Attribute 80 Sh2 Bicolor

GSS 0966 Attribute 78 Sh2 Yellow

WSS 0987 Attribute 81 Sh2 White

BC0805 Attribute 82 Synergistic Bicolor

BC0822 Attribute 77 Synergistic Bicolor

GH0851 Attribute 80 Synergistic Yellow

WH0809 Attribute 80 Synergistic White

Obsession II Perform-ance

79 Sh2 Bicolor

Passion II Perform-ance

81 Sh2 Yellow

Temptation II Perform-ance

72 SE Bicolor

Table 1. Bt Sweet Corn Hybrids on the Market

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WHY USE COVER CROPS

Vaden Fenton, Fruit & Vegetable Extension Associate Farmers and researchers have been using new technology to improve crop production for many years. However some very simple cultural practices can be used to great effect. One such practice is the use of a cover crop. Some of the benefits of cover crops are listed below: Cut fertilizer cost, reduce the need for herbicides and other pesticides, improve soil health and prevent soil erosion When using a cover crop keep in mind the goals you are trying to achieve with the use of cover crops. Are you looking to provide nitrogen, add organic matter, reduce soil erosion, improve weed control or improve soil structure, all these are questions one should ask before deciding on a particular type of cover crop. Cover crops should be planted in the fall and turned under in the spring to increase its efficacy. Growers can choose from a wide variety of plants to be used as cover crop, legumes and grasses, including ce-reals, are the most widely used crops. Cover crops that are grown to increase nitrogen in the soil are called legumes. Legumes have the ability to transform atmospheric nitrogen to soil nitrogen that plants can use. Some examples are sweet clover, hairy vetch and a mixture of peas and oats. These crops are turned under before they mature, at this stage they contain the highest levels of nitrogen and moisture which aid in the rapid decomposition of plant materials. Plants that are left to decay before they are plowed under decomposed at a much slower rate than those plowed under with sufficient moisture. Cover crops sometimes suppress weed seeds from germinating. Cover crops can smother other competing crops and also out-compete weeds for water and nutrients resulting in a reduction of weed seed germination. The canopy of some cover crops also blocks out sunlight from reaching the ground, also reducing the rate of weed seed germination. Some cover crops can be the host of beneficial microbial life and insects that are natural enemies for some pest. Other cover crops can produce a compound that reduces nematodes pest population while others like decomposing winter rye residue can reduce weed seed germination (allelopathic). Build-

ing soil for better crops page 106 To improve the soil health one does not need a syringe but adding organic matter to the soil would do. Plowing under your cover crop will increase the rate of soil drainage; increase the soil organic matter content and increase soil aeration. This can also encour-age beneficial microbial life in the soil to aid in the decomposition process. The cover crop can also alleviate soil compaction and improve the soil’s overall structure. With a cover crop in place wind and water erosion is significantly reduced. The usage of a cover crop provides cover to protect the soil from rain drops and temperature extremes. The roots of these crops hold the soil together and reduce the amount of exposed soil surface, which leads to wind erosion. The rate of infiltration is increased and the amount of runoff is reduced. References Magdoff, F., and Harold Van ES. 2009. Building Soils For Better Crops, Sustainable Soil Management. 3rd edition published 2009 by the Sustainable Research and Education. Managing Cover Crops Profitably. 3rd edition published 2007 by the Sustainable Research and Education.

Rye planted after fall pumpkin Rye use as a cover crop for weed suppression