Category: Vegetable Science

Introduction

A significant section of small and marginal farming community, who constitute 80% of the country’s farm holdings is significantly dependent on the production of vegetables such as various gourds, brinjal, cucumber, tomatoes apart from potatoes, onions etc. (Sindhu et al., 2005).Approximately 70% of the tropical vegetable crop species produced are dependent on the activity of insect pollinators (Klein et al., 2007).This underpins the 7.53 million tonnes of vegetables grown in India representing 13.4 % of global production (Charan et al., 2010) – a sizeable proportion of which is pollinator dependent.

The consideration of pollination requirements for vegetable crops should be viewed in two broad categories.

Vegetable seed production

Vegetable production

Pollination

Pollination refers to transfer of pollen from the anthers or male reproductive organs of the flowers to the stigmas.

 Types of Pollinations

1. Self pollination
2. Often cross pollination
3. Cross pollination

Table 1: Different pollinators which play vital role in pollination

Table 2: List of crops which requires and does’t require the pollinators:

In vegetable production, insecticides can harm pollinators (including bees) in several ways:

1. When pollinators are present, resulting in direct exposure. This can be true for crops that require pollination services and for crops where pollinators are only feeding on pollen.
2. Applicators apply insecticides to fruit or vegetables when pollinators are not present, but the insecticide residues persist long enough to potentially harm pollinators when they visit the crop.
3. Applicators apply systemic insecticides to fruits and vegetables. These products move through the plant to flowers in quantities that could harm pollinators.
4.  Applicators apply insecticides outside the fruit or vegetable production field that move (in some manner) into the field in sufficient quantities to harm pollinators.
5.  The residues of systemic insecticides remain in the soil from a previous crop. The fruit or vegetable crop then takes up the insecticide, which moves to flowers in quantities large enough to harm pollinators.

Best Management Practices to Attract and Protect Pollinators:

• Plant native and other well-adapted flowering plants for season long bloom in or near the garden.
• Create nesting habitat for ground- and cavity-nesting bees.
• Do not spray insecticides or fungicides on flowering plants or fruit trees just before or during bloom.
• If pesticide applications are necessary, choose a product with the least toxicity to bees.

The pollination process:

• Many insects visit flowers to collect pollen and nectar as food. As they forage, these insects spread pollen grains among flowers, accomplishing pollination. Many flowers offer sugary liquid nectar as an added enticement for these pollinating insects. Among insect pollinators, bees are especially efficient because they eat pollen and nectar exclusively, visit many flowers of the same species during a single trip and have hairy bodies that easily pick up pollen grains.
• Cucurbit flowers open shortly after sunrise and remain open until late afternoon or early evening, so each flower is open for only a few hours. The honeybee is the most common and effective cucurbit pollinator. Honeybee activity closely coincides with the period when the flower is open. Honeybees begin to visit flowers an hour or two after sunrise and continue to visit until mid-afternoon. If temperatures are very warm, bee activity may decline about noon. Avoid spraying pesticides when bees are active.

How are vegetables pollinated?

• Vegetable crops that produce a fruit require pollination in order to develop fruit. Some vegetable plants produce a separate male and female flower – pumpkins, squash and cucumbers for instance. Pollination occurs when insects such as bees and hoverflies visit flowers, collecting nectar and pollen.

How do you attract Pollinators to a vegetable garden ?

• How to attract them: Plant large patches of flowers such as vetch, borage, buckwheat, sunflowers, alfalfa, clover, or wildflower mixes to bring them to your yard. You can also hang a honey bee lure in your garden.
• Plants produce nectar to attract pollinators.

How many flowers does a bee pollinate in a day?

• Did you realize that a bee can visit up to 5,000 flowers in a single day? If you think that’s amazing, consider this: to make one pound of honey, a hive of bees must travel over 55,000 miles and visit two million flowers!

What time of day are bees most active?

• Bees are mid-morning risers. Meaning they will be out and about during the day. Early morning could be best if you don’t have time to wait for dry grass. But either way before 9a.m. or after 5p.m. is the best time to mow your lawn to avoid bee stings.

At what temperature do bees die?

• At somewhat lower temperatures bees can survive longer at high relative humidities because desiccation is the limiting factor. PIRSCH (1923) concluded that honeybees die at 46 ° to 48°C and ALLEN (1959) found that they die after 1 hour at 48 °.

Need of management of pollinators:

• Unlike the western countries, the bees that pollinate Indian crops are almost all wild honey bees and other non- Apis pollinators. As a result, very little research has been done on their decline.
• According to Gallai et al. (2009) more than 40 % of honey bees have been disappeared during last 25 years in India

Reference

• Abrol DP. 2009. Plant-pollinator interactions in the context of climate change – an endangeredmutualism. Journal of Palynology, 45:1-25
• Basu P,Bhattacharya R and Ianetta PP. 2011. “A decline in pollinator dependent vegetable crop productivity in India indicates pollination limitation and consequent agroeconomic crisis,” Nature Precedings, http://hdl.handle.net/ 10101/npre.2011.6044.1
• Chakrabarti P, Rana S, Sarkar S, Smith B and Basu P. 2014. Pesticide-induced oxidative stress in laboratory and field populations of native honey bees along intensive agricultural landscapes in two Eastern Indian states. Apidologie 46, 107–129.
• Gallai N, Salles JM, Settele J  and Vaissiere BE.2009. Economic valuation of the vulnerability of world agriculture confronted to pollinator decline. Ecological Economics 68, 810-821.
• George RAT. 2009. Vegetable seed production, 3rd ed. CABI, Wallingford.
• Klein MA, Vaissiere EB, Cane HJ, Steffan-Dewenter I, Cunningham SA, Kremen C  and Tscharntke T. 2007.Importance of pollinators in changing landscapes for world crops. Proc.  R. Soc. Lond. (B) 274,303-313.
• Pannure A.2016.Bee pollinators decline: perspectives from india. International Research Journal of Natural and Applied Science,3(5)
• Raj H and Mattu VK.2016.bee pollination and pollinator friendly management Practices in himachal himalaya, india,Global Journal of Bio-science and Biotechnology, 5 (1) : 88-94
• Sengupta P and Ghorai N.2018.A study on the foraging behaviour of hymenopterans on vegetable crops in the South-24-parganas district of west bengal, india.Asian Journal of Science and Technology, 09(1):7319-7326,
• Sushil SN, Stanley J, Hedau NK and Bhatt JC. 2013. Enhancing Seed Production of Three Brassica vegetables by Honey Bee Pollination in North-western Himalayas of India , Universal Journal of Agricultural Research 1(3): 49-53
• Annual report of AICRP on  Honey Bee and Pollinators, Bhubaneswar, OUAT, 2016-17.

Author Details:

Shaik Moulana

Research Associate, Banana Research Station,

Dr.YSR Horticulture university, Pulivendula,

YSR Kadapa (Dist.), Andhra Pradesh-516390

Email @moulana1995@gmail.com