Temperature the secret to growing happy mungbeans
The perfect temperature to plant
.WELL, the calendar says it is mid November, however the actual weather we have had cannot make up its mind to be either very hot or fairly cool. We have had both of these temperature extremes in Queensland over the past twoodd weeks.
One thing I do know is the closer we get to Christmas the more phone calls I am getting about growing our short and quick mungbean crops. I have spoken strongly in the past about mungbeans disliking that cooler weather we can experience in springtime. By cooler I mean maximum temperatures of, say, 25 degrees C and minimums of about 12 degrees C. This will give a mean or average temp of about 18 degrees. However, for our summer-loving mungbeans the amount of actual heat units accumulated at this stage is going to be very weak at 13 degrees per day. Mungs are classed as chilling sensitive. These coolish conditions mean it is well over 45 days’ development till first flower, if those low temperatures persisted and to accumulate that 550 day degrees for flower initiation.
Utopia for our mungbean plants is that constant 28 to 30 degrees C, however that may only happen in Col Douglas’s (our principal DAF mungbean breeder) new glass house at the Hermitage Research Centre.
No, our mungbeans are mostly going to be planted in December, January and February depending on where you are in regional Queensland and when the rain falls. Temperatures will climb, most likely to about 50 or 60
degrees C ground surface temperatures and that is fairly warm for any crop. However as many of us recognise, our short and quick mungbean crops are a lot tougher than other summer crops. Particularly if our mungbean plants have some moisture around their root zones. Sure, the reproductive stage of mungs would prefer maximum temperatures of less than 40 degrees C, however, in reality in eastern Australia, our
paddock temperatures are never going to remain at that easy temperature of 30 degrees C.
You can see by my attached photo that already mungbeans have been planted in some areas and that earliness simply may reflect our lack of confidence on some significant December or January rain falling.
When farmers or agronomists ask me when is the best time to plant
mungbeans, I reply about 25 to 30 days before a significant rainfall event of around 50mm or more.
This off-hand remark does bear a lot of truth and in my experience is fairly good timing for an inundation event in our early flowering mungbean paddocks.
The weather forecast in December and January is a complete mystery to most of us and I guess future storm rain is the most unpredictable
of events. If mungbeans are on your radar, be sure of your seed supplies and their quality. The AMA has the mungbean seed scheme operating, which provides the best quality seed you can get, however it may not be totally disease free from those very difficult bacterial diseases like tan spot and halo blight issues.
Here’s hoping you all get some rain events for summer and grow profitable crops.
SPROUTING SEEDS: Mungbean seedlings emerging on Darling Downs in 2018 into a zero till paddock.