2. (a)Despite favorable climatic conditions, a farmer's crop failed to give a good yield. Give the possible reasons for this. (b)What is the right time to spray weedicides?

the possible reasons for the poor yield of crops are:

-poor soil nutrient/fertility and non-viable crops.

-lack of technical farming knowledge

-crops/plants destruction by pests, weeds and diseases

-lack of modern technology

The best time to spray weedicides is dry seasons or time when there is no rain.

Explanation:

Soil fertility is one of the major factor that determine the yield of crops. Improper use of fertilisers will destroy soil fertility which will affect crop yield. Non-viable crops will also affect productivity.

Lack of technical know-how of a farmer can cause low yield of crop. Farmers that lack the basic skills of farming cannot improve the yield of crops. Lack of education also can cause low yield of crops.

Crops that are affected pests by diseases will not produce good yields. Lack of viable pesticides to control pests, unavailability of herbicides to control weeds and diseases will result to poor yields of crops.

The use of crude tools will affect productivity. Lack of infrastructure and like proper market settings, good roads and modern farming equipments will result to low crop yields.

The best spraying time is dry seasons

the answer is b: 1.4 km/hr

the backbone of the dna and rna compound is sugar phosphate.