Influence of environmental factors on horticultural crop production

Temperature: It is an important determinant of plant growth. High as well as low 

temperatures influence the growth of plants. Broad leaved, ever green plants are very 

much susceptible to low temperature. Fall of temperature below 5*C put a strain on 

the survival of such plants. Deciduous plants by their adoptive mechanism to shed 

foliage are better able to tolerate low temperature. Such plants pass their lives in 

dormant stage during winter. Generally, a temperature range of 20  - 30*C is 

considered ideal for majority of tropical and subtropical plants. Temperate plants 

require chilling winter. In majority of temperate fruit plants, flowering commencessubject to fulfillment of chilling temperature ranging from 2*C to 7*C.High temperature 

above 40*C causes scorching in plants. The leaves show burning symptom along tip 

and margin. High temperature causes bolting and seed formation in spinach and 

lettuce. Development of red colour in oranges is governed by low temperature. More 

severe winter favours discontinued synthesis of chlorophyll and unmasking of 

carotenoids which imparts red colour to oranges. The optimum temperature for most 

of the plants varies in the range of 22*C to 27*C. High fluctuation in day and night 

temperature badly influences the growth and production of plants.

Hailstorms: These causes great damage to the fruit crops. Occurrence of hail at the 

time of flowering and fruit maturity is very disastrous because flower and fruit drop is 

heavy and the growers get poor returns for their produce. For successful cultivation of 

fruit crops, only those areas where hailstorms don‘t occur should be selected.

Solar radiation: It is the primary source of energy to plants. For the transformation of 

light energy to chemical energy leading the production of photosynthates, solar 

radiation is must. Orchard, located on southern side of the slope receiving better 

amount of radiation, bears better yield than other side. The periphery and top most 

portions of plants are more productive due to better and direct absorption of solar 

radiation. Training and pruning of plants are maneuvered in a way; so that the plant 

may be better able to absorb more solar radiation required for good productivity.