No abstract

Functions of sodium (Na+) and potassium (K+) are closely associated. In some crops, Na+ is able to prevent or reduce considerably the occurrence of K+ deficiency. Sugar beet (Beta vulgaris L.) is a natrophilic crop, and positive effects of Na+ applications on yield were observed when K+ was sufficiently supplied. However, it is not known which specific function of K+ can limit the growth of sugar beet when K+ is substituted by an equivalent amount of Na+. Therefore, K+ substitution by Na+ was investigated for sugar beet in hydroponics. Surprisingly, no K+‐deficiency symptoms were observed. However, calcium (Ca2+) concentrations in the leaves were significantly decreased. Moreover, Ca2+ uptake and translocation through xylem sap were reduced in Na+‐treated plants. It is concluded that Ca2+ uptake by roots and its translocation via xylem sap primarily limit the possibility of K+ substitution by Na+ in sugar beet nutrition.

The present study was conducted at district Kom Ombo sugar cane farms, (latitude of 24 o 28 o N and longitude of 32 o 57 o E), Aswan Governorate, in the two seasons of 2015/2016 and 2016/2017 including plant cane and 1 st ratoon crops, respectively. To study the effect of harvesting age and phosphorus fertilization levels on yield and quality of some sugar cane varieties. Field experiment included twenty-seven treatments represented the combinations among three harvesting ages (10, 11 and 12 months) three phosphorus fertilization levels [30, 45 and 60 kg P 2 O 5 /fad.] and three sugar cane varieties [G.T. 54-9, G.2003-47 and G.2004-27]. Randomized complete block design with three replications laind aut in split-split plots arrangement.The results showed that all of the studied traits were significantly influenced by the harvesting ages. The three sugar cane varieties significantly differed in all studied traits. The new commercial sugar cane variety G.2003-47 showed superiority over the other varieties in brix sucrose purity cane and sugar recovery percentages. Increasing phosphorus level from 30 up to 60 kg P 2 O 5 /fad. increased significantly brix, sucrose, purity and sugar recovery percentages, while cane and sugar yield tons/fad., in plant cane crop, only.Our data suggest that farmers should attempt to harvest the majority of their crop at age of 12 months. With fertilization by 60 kg P 2 O 5 /fad. to maximize yield.

Two field experiments were carried out during two summer seasons (2017 and 2018) at the Experimental Farm of the Faculty of Agriculture, Assiut University, Assiut, to study the response of two maize hybrids [Single Cross 128 (S.C. 128) and Triple Cross 310 (T.C. 310)] yield and its components for three interrows spacing (Rw 1 = 60 cm, Rw 2 = 70 cm and Rw 3 = 80 cm) and three intra-rows spacing (S 1 = 20 cm, S 2 = 25 cm and S 3 = 30 cm). Experimental design was randomized complete block design (RCBD) using split-plot in strips, where interrow spacing allocated in the main horizontally, maize hybrids were arranged in the main vertically and intra-row spacing were occupied the sub-plots. According to results, the maximum values of plant height and ear diameter in both seasons, ear length in the 1 st season, ear grains weight and grain yield/fed.

A field experiments was carried out during of 2014/15 and 2015/16 seasons in the Experimental Farm, Agricultural Research Station of El-Kharga, New Valley Government to study the effects of partially substitution of chemical NPK fertilizers by biofertilizers on two barley cultivars production under New Valley conditions. Seven fertilizers combinations were tested as follows: F 1 : 100% of recommended NPK fertilizers, F 2 : 75% of recommended NPK fertilizers + Microbein, F 3 : 50% of recommended NPK fertilizers + Microbein, F 4 : 75% of recommended NPK fertilizers + Algae extract, F 5 : 50% of recommended NPK fertilizers + Algae extract, F 6 : 75% of recommended NPK fertilizers + Algae extract + Microbein, and F 7 : 50% of recommended NPK fertilizers + Algae extract + Microbein. Number of spikes m-2 , number of grains spike-1 , weight of 1000-grains, weight of grains spike-1 , biological yield fed-1 , grain yield fed-1 , straw yield fed-1 , and harvest index (%) were recorded at harvest. Results indicated that the superiority of Giza 134 cultivar over Giza 132 cultivar was confirmed for most studied traits in both seasons. Double-inoculation of Algae extract and Microbein plus 75% of recommended mineral NPK fertilizers represents 10.14, 18.50 and 16.19% increases in grain, straw and biological yields of barley in the first season; 8.91, 29.42 and 22.15% in the second season, respectively; compared to the application of 100% of recommended mineral NPK fertilizers alone. Giza 134 cultivar fertilized with 75% chemical NPK + Algae extract + Microbein (F 6) gave the highest grain yield (2.69 and 2.97 ton fed-1) and biological yield (8.38 and 9.43 ton fed-1) followed by 50% chemical NPK + Algae extract + Microbein (F 7) with the same cultivar (2.53 and 2.88 ton fed-1) and (8.16 and 8.95 ton fed-1), respectively. It can be concluded that replacing 25 or 50% of chemical fertilizers by doubleinoculation of Algae extract + Microbein as biofertilizers to improved yield and its components of Giza 132 and Giza 134 cultivars as well as saving about 25 to 50% of recommended dose of NPK.