Cucurbits - Loofah

[Farmer Bob]

Hi. I'm Bob and new to the forum. I reside in Cape Town, South Africa. I have been experiencing low yields with loofahs I am growing. I plant seeds in early Spring and the vines start flowering within a month. We do not have many bees ( if any )around and so I hand pollinate the female flowers. Some develop into beautiful mature fruit, whereas others start developing, but suddenly wither and dry up. Others will wither and dry even before the female flower opens . I water twice daily and feed every fortnight. Can anyone explain why this happens.? Thanks

[rainbowgardener]

Welcome to the forum, Farmer Bob; glad you found us. I have to start by admitting that I didn't even know that loofah was something you grow! So clearly not an expert. But you say it is a cucurbit and I have experience growing other cucurbits, zucchini, butternut squash, etc. If you were talking about a cucurbit I was familiar with, I would think that what you are describing is the attack of the squash vine borer (aka zucchini root borer). Type those terms into the Search the Forum feature and you will find lots written here about them. Even if there in South Africa you don't have the exact same insect we do, you probably have something similar.

Here's one thread to start you off and it has links to others

https://www.helpfulgardener.com/forum/viewtopic.php?p=109343&highlight=squash+vine+borer#109343

[Farmer Bob]

Hi rainbowgardener,

Thks for the info. Will check it out. I'm a keen veg gardener and enjoy growing unusual vegs like bitter gourd, loofah, wax gourd and different varieties of Chinese cabbages in the different seasons. I also have a custard apple tree ( Cherimoya ) which only bore 3 fruits last year. this year, I learnt all about hand pollinating on Google and now I have 50+ fruit that have set.! They sell for about R50 ( US $ 7 ) a piece in the retail fruit and veg stores.!

[tedln]

Hi Bob,

Welcome to the forum. I grew Loofah for many years. I had a lot of fun with them and even ate a few. I mostly grew them for the sponge when dried.

I had very few problems with them. From what you are describing, it does sound like an insect problem or an insufficient pollination problem. I have no idea what insect pests are present in South Africa. From the little I've read about South Africa, I think you probably have more pests than we have in the states.

From history, when the Dutch and trekboers first settled South Africa and Rhodesia (Zimbabwe), they attempted to plant and grow the same crops or types of crops they grew in Europe. Because of the latitude closer to the equator and different insect pests, the crops simply would not grow. They nearly starved to death. That may be part of the problem you are having with your Loufah. I don't know where Loufah originated but I think it is more accustomed to climates in Taiwan and cooler climates of China.

I don't really think they are susceptible to squash vine borers. I say that because I would grow squash less than ten feet from the Loufah. The borers would attack the squash and not attack the Loufah at all.

I do know from my experience, the vines require huge amounts of water and nitrogen. I had to fertilize with lots of Ammonium Nitrate. I don't think it is possible to over fertilize them. My vines would grow up trees in excess of thirty feet and the fruit would exceed thirty six inches long.

I also seem to remember the Loufah is a climbing vine and does not perform as well as a vining crop on the ground.

I hope this information helps.

Ted

[Farmer Bob]

Hi Ted,
Thks for the input. Yes, I agree. I do not think I have a vine borer problem.There is no evidence of insect damage either. I feed the plants fortnightly with chicken manure, which is very rich in Nitrogen ( Organic gardening). My plants are healthy and I have them growing up trellises. Temperatures here are between 70 - 90 deg F. Perhaps the problem is temperature related. However, I have more success than defective fruit. All my plants are grown in containers because I lack big pieces of land. Likewise, we have more than use and bless friends , relatives and neighbours as well.! nothing like home-grown veg.! Just a thought. You probably have heard of fruit dropping. Do you think this applies to veg as well.? Google it and let me know.
Regards, Bob

[tedln]

Fruit drop could easily be the problem. I didn't know you were growing the Loofah in containers. Considering the vigorous growth rate of the vine and fruit, I would assume it also has a vigorous root system. I've done a lot of container gardening and never considered growing Loofah in a container but have grown a lot of cucurbits in containers.

Fruit drop to me is a purely defensive measure plants take to help insure the survival of the plant during periods of stress. In nature it seems it is more important to insure the survival of the plant with the possibility the plant can produce offspring in future periods of low stress.

I'm curious about the climate and elevation you garden at. Is Capetown more of a temperate climate than most of South Africa? You mentioned you are growing Cherimoya and I believe they are native to certain elevations of the Andes mountains in South America. I'm surprised they will grow in Capetown.

Ted

[Farmer Bob]

Hi Ted,
Cape Town is has an elevation of 6m . We have Mediterranean climate here. Dry hot summers and wet cold winters.Summer Temp. about 70-90 deg F.

I'm doing well with Cherimoya, since the hand pollinating. From 5 fruits last year ( Natural pollination) to 50+ fruits this year thru Hand Pollinating. the tree is about 10 years old.

Take care.
Bob

[tedln]

Are you also growing the Cherimoya in a container? Can you post some photos? I would love to see your containers and the size of the plants and fruit. Are you also raising chickens? Sounds like you are attempting to create a self contained food cycle.

Ted

[Farmer Bob]

Hi, My chayote , bitter gourd and second phase of loofahs have suddenly been attacked by the pumkin fruit fly Bacterocera decipiens. which stings the fruit and lays its egga in the fruit. These stings stunt the fruit and larvae which can jump start hatching in the fruit and they eat the maturing seeds in the fruit. One does not often see the fruit fly around, but damage becomes evident after a while.

As I aim to practice organic gardening, I do not want to use chemical pesticides. Any advice on natural control .?

Gladly welcome some input here please.[/I]

[Farmer Bob]

Hi, My chayote , bitter gourd and second phase of loofahs have suddenly been attacked by the pumkin fruit fly Bacterocera decipiens. which stings the fruit and lays its egga in the fruit. These stings stunt the fruit and larvae which can jump start hatching in the fruit and they eat the maturing seeds in the fruit. One does not often see the fruit fly around, but damage becomes evident after a while.

As I aim to practice organic gardening, I do not want to use chemical pesticides. Any advice on natural control .?

Gladly welcome some input here please.[/I]

[rainbowgardener]

If they've already been attacked, it's too late for this, but for future reference one thing that helps prevent all this kind of attack is to grow your crops under floating row cover.

https://gurneys.com/product.asp?pn=2005&utm_source=cs&utm_medium=base&bhcd2=1269109222

That's what I will be doing this year for my cucurbits, to keep the root borers away.

Once the eggs are in the fruit, I would think there's little you can do-- they would be protected from anything sprayed on the outside.

Here's an article about integrated pest management techniques for these pests, including trap crops and a protein bait with spinosad. Spinosad is being touted as an organic insecticide. It is a bacterial exudate. But it is a broad -spectrum insecticide harmful to honeybees while wet. But I would imagine honeybees would not be attracted to the protein bait, so would not be impacted by this usage.

[tedln]

Bob,

Are you sure it is the Pumpkin fruit fly? According to the following link, the only known occurance of this pest is in the Papua, New Guinea region of the Pacific.

https://www.spc.int/pacifly/Species_profiles/B_decipiens.htm

Pumpkin has also supposedly been identified as the only host of the pest.

Just curious.

Ted

[applestar]

Setting sticky traps is a good way to ID fruit pests. If you're seeing such a damage, you can wrap a ball with plastic wrap and slather products like Tanglefoot which is sold for the purpose, or petroleum jelly or other unscented sticky product. I don't have the kind of fruits you have, but for apples, you're supposed to hang green small balls for pests attacking green apples and red balls for pests attacking red apples, so similar technique will probably apply.

I honestly haven't used the product enough to form an opinion, but I started to use, and am going to use again this year, Surround -- superfine milled kaolin clay -- in liquid suspension. The white clay coating is supposed to visually and [the smell -- what's the word for that?] - ly confuse them, and physically block them as well.

[rainbowgardener]

The white clay coating is supposed to visually and [the smell -- what's the word for that?] - ly confuse them, and physically block them as well.

olfactorily

[Farmer Bob]

Hi Folks, Thks for all the advice on my fruit fly problem. Will give it a try. I logged onto Google and was directed to www.africamuseum.be which showed some pics of the pests They certainly look like the ones that have been attacking my cucurbits. Probably one of the types if not Bac.decipiens. Ted , you were correct in saying they originate in Asia/Pacific areas. Apparently they have become invasive in Africa.
We are going into Autumn ( the fall) this side of the world and I'm going to be planting different Brassicas and having a go at daikon ( Giant Japanese radish ). Enjoy your Spring/Summer plantings and all the best for bumper crops. !