A brief summary of the origin and relevancy of crop protection in Agriculture
The struggle against pests, diseases and weeds commenced at the time that primitive man changed his life style from that of a nomadic hunter to that of a cultivator of crops.
Throughout history we read about the devastating effects of the outbreaks of insect pests and plant diseases. A serious famine occurred for example in Ireland during the 1840’s due to the outbreak of Late blight of potatoes caused by the fungi Phytophthora infestans. More than 700 000 germans died of famine and disease due to a potatoe crop failure caused by Late blight and insects at the end of World War 1.
Since the dawn of Agriculture pests, diseases and competition by weeds have reduced the productivity of crops and farmers have been looking for ways and means of limiting these losses and of growing healthier crops in other words they have been taking steps to protect their crops. In general the more intensive the systems of cultivation, the larger are the potential losses due to harmful organisms.
It is inevitable that pathogens and pests will infect or attack crops and that weeds compete with crops for water and nutrients, thereby reducing yields. Plants will not produce reliable yields of high quality unless they are kept healthy. In all of this, crop protection products play a significant role.
In wheat it is estimated that without crop protection but otherwise unchanged cultivation practices crop losses worldwide are 16,7% due to diseases, 11,3% due to insect pests & 23,9% due to weeds (Oerke et al, 1994). Comparative loss figures for Southern Africa are 15% due to diseases, 30% due to insects and 20% due to weeds.
In maize the average losses suffered worldwide without crop protection is estimated to be 11,7% due to diseases, 19,1% due to insects and 28,8% due to weeds, total 59,6% (Oerke et al, 1994). In Southern Africa the comparative figures are 10%, 20% & 40%, total 70% loss of yield potential.
The estimated average losses in potatoes worldwide without crop protection are 24,4% due to diseases, 26,4% due to insect pests, and 22,8% due to weeds, giving an overall figure for losses of 73,6%. For Southern Africa the comparative losses are 40%, 25% & 15% (Oerke et al, 1994).
In Cotton, the loss worldwide without crop protection is estimated to be 83.5% i.e 10,2% due to diseases, 37% due to insect pests and 36,3% due to weeds. Southern African comparative figures are 10%, 55% and 25% (Oerke et al, 1994).
Advances in Crop Science and Technology Journal