The sowing date trials comprised of three planting dates on three cotton varieties (Lachata, Stoneville 213 and Coker 310), were conducted to investigate appropriate sowing time of the varieties at Erbil, Kurdistan during 2017. It was also to investigate the effect of climate change of sowing time. Results indicated that sowing dates, varieties and interactions significantly affected all studied characteristics. The highest plant height was recorded of Stoneville 213 which was by (110.8) cm in April 27. Variety Lachata exhibited maximum seed cotton yield (5851.13) kg/ha followed by variety Coker 310 (5097.77) kg/ha on March 28. The different results of mean boll weight, number of seeds per boll, seed index and other parameters were also recorded for varieties and different sowing dates. It was concluded that sowing on March 28 is the most appropriate sowing time for these varieties under agro-climatic condition of Erbil, Kurdistan. Based on the results from this current study some varieties will be growing better in other state of Kurdistan especially in the cold condition.

The aim of this study was to determine the effect of potassium, boron and zinc rates on the growth of kenaf. Seeds of two kenaf varieties namely; FH-952 and 4383 variety were planted on 26 September 2013. Plant growth was determined for both varieties. The growth characteristics which consist of plant height, stem diameter and leaf number were measured every two weeks for five times consecutively. The best result was achieved for both characteristics; stem diameter and leaf number for FH-952 variety when potassium and boron added at rates of 150 and 1.5 kg/ha, respectively except plant height was better when potassium was at the same rate while boron and zinc were controlled. The results showed a significant impression on the kenaf growth. It would be apposite to choose better varieties of kenaf for the production purpose with using better controlling of macro and micronutrients.

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Nitrogen, phosphorus and potassium are regarded as the main nutrients necessary for plant growing. Each of these fertilizers has significant effects on plants growth. Their functions are somehow in relationship to each other. The purpose of this article is to show the importance of the potassium nutrient on the crops life. This kind of nutrient is disregarded in Kurdistan. Generally, the farmers have not information about the impacts of potassium. Hopefully, this study will encourage scientists to do more research on effects of potassium on plants. On the other hand, this article is going to be a key for using potassium fertilizer as an important mineral for the crops in the Kurdistan at the best way. Two factors are more important for every farmer to know before using the fertilizers (Fertilizers cost and environment pollution). As known, for getting fertilizers farmers must be paid, and fertilizers can damage the environment if these are not used correctly. Hence, for solving the above problems, a soil sample must be sent to a laboratory for physical and chemical testing before application of fertilizers. Farmers must know about appropriate nutrients and amount to add to the soil. Application of little amount of nutrients cannot grow crops and too many nutrients can run off the fields and pollute streams and ground water. Fertilizers have important purpose and function. Hence, farmers must be careful to practice the right dose, at the right time, to avoid negative effects of the fertilizers on the environment.