Two field experiments were carried out at Gemmeiza Agric. Res. Station, El-Gharbia Governorate during 2010 and 2011 seasons, to study the effect of four NPK fertilizers rates (100 %, 75 %, 50 % and 25 % of recommended rate) and application methods of humic acid on growth of the Egyptian cotton cultivar "Giza 86". The recommended rate of NPK was 45 kg N +22.50 kg P2O5 + 24.0 kg K2O/ fed.. The solutions of humic acid were applied with the concentration of 5 cm 3 /litre as a soaking seed for 18 h, 50 cm 3 /litre as soil application twice , 5 cm 3 /L as a foliar application at 40, 55 and 70 days from sowing and without humic acid as a control treatment. Leaf area index (LAI), total dry weight/plant, crop growth rate (CGR), plant height and number of fruiting branches/plant were significantly increased by increasing NPK rate from 25 up to 100% of the recommended rate at all sampling dates in both seasons. Also, application of 100% NPK recorded the highest net assimilation rate (NAR) at the first period (79-100 days) in the two seasons. Application of humic acid solution resulted in a significant increase in all mention growth measurements (except NAR) compared with control treatment in both seasons. Foliar application of humic acid resulted in a significant increase in leaf area index, total dry weight/plant, crop growth rate, plant height and number of fruiting branches/plant compared with other application methods in both seasons. The interaction between NPK rate and humic acid application had a significant effect on LAI, total dry weight/plant, CGR and NAR at the most sampling dates in the two seasons. Plants received 100 or 75% NPK along with foliar application of humic acid produced higher LAI, total dry weight/plant and CGR than those received 25 % NPK and without humic acid at the most sampling dates in both seasons. The relative ranking of the interaction between NPK rate and humic acid application for NAR was inconsistent at the two period in both seasons. None of the interaction had a significant effect on plant height and number of fruiting branches / plant in the two seasons. It can be concluded that 75% NPK and foliar application with humic acid could be recommended for optimum dry matter production of the Egyptian cotton cultivar "Giza 86". This result indicated that foliar application of humic acid can be saved 25% NPK fertilizer without reduce growth of cotton plant.

Two field experiments were carried out at El-Gemmeiza Agricultural Research Station, El-Gharbia Governorate in 2014 and 2015 seasons, to study the effect of nano-fertilizer (Lithovit) rates (0, 2.5, 5 and 7.5 g/l) and foliar potassium fertilizer (in the form of Potasin-P) rates (2.5, 5 and 7.5 cm 3 /l) under three planting dates (8 April, 8 May and 8 June) on leaves chemical composition of the Egyptian cotton (Gossypium barbadense L.), cultivar Giza 86. Cotton plants were foliar sprayed with Lithovit and Potasin-P at 45 and 60; 46 and 61 days after planting, respectively. Leaves N, P, K, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates contents were significantly affected by planting date in both seasons, in favour of early planting date (8 April) compared to medium and late planting dates (8 May and 8 June). Delaying planting date significantly increased leaf proline content and leaf peroxidase activity which indicate the presence of heat stress effect on the plant.Leaves N, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates contents were significantly affected by rates of Potasin-P in both seasons, in favour of the medium rate of Potasin-P (5cm 3 /l). While, leaves P and K contents were significantly increased by using the high rate of Potasin-P (7.5cm 3 /l). The medium rate of Potasin-P (5cm 3 /l) significantly decreased leaf proline content and peroxidase activity which indicate favorable plant conditions.Leaves N, P, K, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates contents were significantly increased by each increment of nano-fertilizer (Lithovit). The inverse was true in leaf proline content and peroxidase activity. The decrease in these traits induced favorable plant conditions and reflected on reduce environmental stress effect.The second order interaction had a significant effect on all studied chemical composition of leaves. Cotton plants sown on 8 April and sprayed with 5cm 3 Potasin-P /l and 7.5 g Lithovit/l recorded the highest values of N, P, K, chlorophyll a, b, total chlorophyll, carotenoids and total carbohydrates content in leaves. In the contrary, this interaction recorded the lowest values of leaf proline content and peroxidase activity which induced favorable plant conditions and reflect on reduce environmental stress effect. It can be concluded that the mentioned interaction was the recommended treatment for optimum chemical composition of cotton leaves under experimental conditions.

Two field experiments were conducted on a clay soil at El-Gemmeiza Agricultural Research Station, (Latitude: 30.79, Longitude: 31.12 Altitude: 5), El-Gharbia Governorate, Egypt in 2014 and 2015 seasons, to study the effect of nano-fertilizer (Lithovit) rates (0, 2.5, 5 and 7.5 g/l) and foliar potassium fertilizer (in the form of Potasin-P) rates (2.5, 5 and 7.5 cm3/l) under three planting dates (8 April, 8 May and 8 June) as well as their interactions on cotton growth, earliness traits, seed cotton yield and its components of the Egyptian cotton cultivar Giza 86.Cotton plants were foliar sprayed with Lithovit and Potasin-P at 45 and 60; 46 and 61 days after planting, respectively. A strip split plot design with four replicates was used in both seasons. The important results could be summarized as follow: At the first sampling date, the greatest values of leaf area per plant and leaf area index were obtained from the third planting date in both seasons. At the second sampling date in the second season, the highest values of leaf area per plant and leaf area index were obtained from the first planting date. At the third sampling date, the highest values of leaf area per plant and leaf area index were obtained from the second planting date in the first season and from the first planting date in the second season. Total dry weight per plant significantly responded to planting dates at the three sampling dates in both seasons. At the first sampling date, the third planting date (8 June) resulted in the highest values of total dry weight/plant in both seasons. Planting dates had a pronounced effect on boll setting percentage, boll shedding percentage and 1 st picking percentage over the two seasons of study. Early planting date on 8 April significantly increased boll setting percentage and 1 st picking percentage and significantly dccreased shedding percentage as compared with the medium planting date on 8 May and the late planting date on 8 June in both seasons. Plant height reached its maximum for the third planting date (8 June) followed by the second date (8 May) and the least resulted from early planting in the first date (8 April), while number of fruiting branches/plant reached its maximum for the first planting date (8 April) followed by the second planting date (8 May) and the least resulted from late planting (8 June). Time of planting exhibited significant differences in boll weight, number of bolls/plant, seed cotton yield / plant and seed cotton yield per feddan in both seasons, where the heaviest bolls resulted from the first planting date. Delaying planting date significantly reduced number of bolls/plant and seed cotton yield / plant. Also, delaying planting date decreased seriously the seed cotton yield per feddan in both seasons. Foliar spray of Potasin-P at the rate of 5 cm 3 /l twice at 45 and 60 days after planting resulted in the highest leaf area/plant and leaf area index at the three sampling dates in the first season. In the second season, foliar spray of Potasin-P at the rate of 7.5 cm 3 /l re...

Four field experiments were conducted during four successive seasons of 2001, 2002, 2003 ant 2004 at EL-Manzalla district, Dakahlia Governorate in the salt affected regions, which close to Manzalla Lake, Egypt. The experiments were conducted to known weeds species associated with rice crop as well as to produce a program for controlling all weeds in rice fields with herbicides without any effect on rice yield. These treatments were included four herbicides with three different rates as well as three mixture combinations, hand weeding at two times at 30 and 45 days after planting and weedy check. The obtained results could be summarized as follows: Survey of common weed species associated with rice in salted affected regions which close to Manzala Lake, were Eleocaris geniculata which was the predominant weed with the highest frequency and density at proportion of 76.6 % weed flora, Cyperus difformis which recorded the second rank 10.8 %, the occurrence of Echinochloa curusgalli reached 6.5 % and Ammannia spp. rank for four number in important 6 % in both seasons. All weed control treatments gave better control number of total weed/m 2 , fresh weight of all weeds/m 2 and dry weight of total weeds g/m 2 as compared with weedy check. The tankmixed application of bispyribacsodium plus pyrazosulfuronethyl at (16 + 10 g ai/fed) released 100 % control of all weeds at 60 days after planting. The results indicated that all weed control treatments significantly increased panicles length (cm), panicles weight (g), 1000-grain weight (g) and grain yield (t/fed). The tankmixed herbicide of bispyribacsodium plus pyrazosulfuronethyl at (16 + 10 g ai/fed) produced the highest grain yield (t/fed), while the lower grain yield (t/fed0 produced from the weedy check treatment. Scientific name Family name English name Arabic name Eleocaris geniculata Cyperaceae Brush ‫القرد‬ ‫شعر‬ Cyperus difformis Cyperaceae Small umbrella flower ‫العجيرة‬ Echinochloa crus-galli Poaceae Barnyard grass ‫الدنيبة‬ Ammannia spp: (A. multifolia, A. baccifera and A. auriculata) Lythraceae Redstam ‫الحمامة‬ ‫رجل‬