Effect of mineral and biological nitrogen fertilization on thompson seedless grape transplants [electronic resource]: I.effect on vegetative growth.

Includes references.

A pot experiment was carried out in 2001 and 2002 seasons on Thompson Seedless grape transplants to study the effect of two sources of nitrogen fertilizers (mineral and biological) on vegetative growth of transplants. The experiment included t1uee levels of mineral nitrogen (M1=zero, Mr5 and M3= 109 N I plant I year)and four levels of biological nitrogen (BI=zero, B2=50,B3=100 and B4=200ml of liquid culture of Azotobacter chroococcum). Thus. the study is a factorial experiment in a ranndomized complete block design. Generally, in both the two seasons fertilizing with medium level of minera1 nitrogen M2(5g N / plant / year) gave the highest significant values of shoot length. number of leaves, total chlorophyll content and fresh & dry weights of whole plant. On the other hand, fertilizing with the third biological nitrogen level (B3 = 100 ml / plant / year) gave the highest significant values of shoot length, number of leaves and total chlorophyll content in both the two seasons. Regarding the interaction in both the two seasons. fertilizing with mineral nitrogen alone [treatments (M2 x B1) and (M3 x B1)]increased plant growth (shoot length. number of leaves, leaf area and fresh & dry weights of whole plant) compared with wlferti1ized transplants [treatment (M1 x B1) ]. On the other hand. fertilizing with biological nitrogen alone[treatments (M1 x B2, (M1 x B3) and (M1 x B4) ] increased plant growth (shoot length. number of leaves, leaf area and fresh & dry weights of whole plant) compared with unfertilized transplants [treatment (M1 x B1) ] and the promosing biological treatment was (M1 xB1) in the two seasons . When combining mineral nitrogen with biological nitrogen. higher values were obtained especially when combining the second rate of mineral nitrogen with any di1ferent rate of biological nitrogen. However, the highest values were obtained by treatment (M2 x B3) for shoot length, number of leaves, leaf area and chlorophyll content. Moreover, the highest values of fresh and dry weights of whole plant were obtained by treatments (M2 x B2) and (M2 X B3) In other words, combining mineral with biological nitrogen created more beneficial effect on vegetative growth than adding any fonn alone and the recommended treatment was (M2 x B3)

Summary in Arabic.

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