IntroductionPotato crop requires relatively high amounts of N, P, and K for maximum yield. Soils in the Kingdom of Saudi Arabia are usually deficient in N and P. Furthermore, previous research work showed that soil available K is not sufficient to produce high potato yield without K fertilizer supplement.

Objectives1. Study the effect of compound fertilizer as a sole source of P and K2. Determine the rate of 11-29-19 that would give farmers profitable yield

Experimental DesignField experiments were conducted in summer 2004 and 2006 in the Hail region of Saudi Arabia using a complete randomized block design with 6 fertilizer levels (0, 600, 700, 800, 900, and 1000 kg of 11-29-19/ha) and 4 replications.

ConclusionsThis study demonstrated that soil application rates of 700-900 kg/ha of 11-29-19 at pre-planting increased fresh tuber yield significantly and economically.

ObservationsThe soils in both farms contained low P and low to medium K and have no other limitations for potato production. Both fields have good irrigation water quality. Field observations were made during crop growth and all pointed out to satisfactory plant growth except some leaves scorching in the beginning of the first season due to sandy storms. Poor plant stand was observed in the second season due to lower seed quality and poor weed, insect and disease control. Leaf burning due to herbicide application was also observed early in the season.

Results Leaf N and P concentrations at 45 days after emergence were increased with increasing levels of 11-29-19 in the first season, but no significant difference was detected in the second season. Leaf K concentration was not significantly affected in neither season. Leaf nutrient concentrations were at or above optimum levels for high yield. Addition of 600 kg/ha of 11-29-19 significantly increased yield of fresh market potatoes and one ton/ha of 11-29-19 gave the highest yield in the first season. During the second season, addition of 800 kg/ha of 11-29-19 significantly increased potato yield and the rate of 900 kg/ha of 11-29-19 produced the highest yield. Although the yield obtained in the second season was lower than the first season due to the fore-mentioned field observations, the trend of response to addition of 11-29-19 fertilizer was similar in both seasons.

Effect of compound fertilizer as a sole source of P and K on potato yieldEffect of compound fertilizer as a sole source of P and K on potato yield K. M. Al-Rohily1, A. H. Abdelgadir1, H. M. Sarhan1, and M. Zekri2

1Saudi Basic Industries Corporation, P.O. Box 42503, Riyadh 11551, Saudi Arabia2University of Florida, Hendry County Extension Office, P.O. Box 68, LaBelle, FL 33975, USA

Effect of 11-29-19 fertilizer on potato yield in summer 2004 Effect of 11-29-19 fertilizer on potato yield in summer 2006

Soil preparation and plantingExperimental treatments and irrigation system

Potato crop just before harvest