BT403 Final Term Current Papers Spring 2024 by Muhammad Zaman

Monitoring the Growth of Culture

To monitor the growth following should be checked:

•  Fresh wt. and Dry wt.

Advantages of biofertilizers / Role of bio fertilizer

Biofertilizers are known to play a number of vital roles in soil fertility, crop productivity and production in agriculture as they are ecofriendly and cannot at any cost replace chemical fertilizers that are indispensable for getting maximum crop yields. Some of the important functions or roles of Biofertilizers in agriculture are:

• They supplement chemical fertilizers for meeting the integrated nutrient demand of the crops.
• They can add 20-200 kg N/ha year (eg. Rhizobium sp 50-100 kg N/ha year ; Azospirillum , Azotobacter : 20-40 kg N/ha /yr; Azolla : 40-80 kg N/ha; BGA :20-30 kg N/ha) under optimum

soil conditions and thereby increases 15-25 percent of total crop yield.

• They can at best minimize the use of chemical fertilizers not exceeding 40-50 kg N/ha under ideal agronomic and pest-free conditions.
• Application of Biofertilizers results in increased mineral and water uptake, root development, vegetative growth and nitrogen fixation.
• Some Biofertilizers (eg, Rhizobium BGA, Azotobacter sp) stimulate production of growth promoting substance like vitamin-B complex, Indole acetic acid (IAA) and Gibberellic acids etc.

Advantages and disadvantage of herbicide

Advantages of using herbicides

• Broad spectrum of weeds controlled
• Reduced crop injury
• Reduced herbicide carryover
• New mode of action for resistance management
• Crop management flexibility and simplicity
• Use of herbicides that are more environmentally friendly

Disadvantages of herbicides

• Mammalian toxicity
• Eco toxicity
• Weeds become super weeds
• Reduced crop yield
• Creates soil and air pollution

Herbicides also damage the Crop plants along with weed Outcomes of controlled pollination in plants. Controlled pollination of plants led to the realization that specific crosses could result in a new generation that performed better in the field than either of the parents or the progeny of subsequent generations, i.e. the expression of heterosis through hybrid vigour was observed. Because one of the two major activities in plant breeding is manipulating genetic variability, a key prerequisite to successful plant breeding is the availability of genetic diversity. Principle of anther culture medium. The principle of anther culture medium is to provide a nutrientrich and controlled environment that supports the growth of haploid plant cells derived from anthers. This medium contains essential nutrients, carbohydrates, growth regulators, vitamins, and a solidifying agent to facilitate pollen germination, cell