Which one of the following is not an application layer

What is the agricultural practice of cultivating two or more crops simultaneously on the same piece of land, without following a specific row arrangement?

The system of growing same crop on same land year after year is known as: 

Which is a C₃   plant?

Which of the following pair is not correctly matched?

The character of a special plant variety ,”Antibiosis” refers to:

 When a company identifies the parts of the market it can serve best and most profitably, it is practicing ________.

Which element is maximum in black soll:

Root secrete weak organic acids which attack the rocks and start to dissolve away the softer parts are 

Single seed descent method is a modification of:

Which Phytophthora species is responsible for causing Buckeye rot in tomatoes?